The invention relates to a hinge for knee joint orthoses, knee joint prostheses and/or braces that includes at least one first hinge bracket assigned to the lower leg and at least one second hinge bracket assigned to the upper leg, which hinge brackets are overlappingly connected to each other with their ends in such a manner that with increasing angle between the hinge brackets, a combined rolling and sliding movement is effected in the plane defined by the two hinge brackets, wherein in the overlapping end of one hinge bracket, curves are cut out and at the overlapping end of the other hinge bracket, guide elements interacting with the curves of the other hinge bracket are provided.
The terms “rotating”, “rolling” and “sliding” are interpreted differently in connection with the movements taking place in a knee joint. A rotational movement in the technical meaning is usually the rotation of a body about a stationary axis. A rolling movement in the technical meaning can be compared with a wheel that rolls on a flat surface, wherein the center of the wheel moves in the direction of the rolling movement. A sliding movement in the technical meaning is the displacement of a body relative to another body or to its underlying surface, comparable to a blocked wheel that is displaced on a flat surface (e.g., skid mark).
A simultaneous rolling and sliding movement as it takes place in the knee joint is comparable in this context with a wheel that rolls on a flat surface wherein, however, the center of rotation is displaced in the direction of the movement by a value that is smaller or greater as it would mathematically correspond to the rolling movement (analogous to spinning or locking wheels of a vehicle).
The object of the present invention was a hinge of the aforementioned type which, by means of a variable center of rotation, optimally recreates the kinematics of the natural human knee.